Thin plate heat pipe

ABSTRACT

Disclosed is a thin film heat pipe suitable for removal of hot spots in displays such as an LCD, an LED, and a PDP. An exemplary embodiment of the present disclosure provides a thin plate heat pipe including: a body part having a flat plate shape; a through-hole formed in the body part in a longitudinal direction; a plurality of grooves formed on the inner wall of the through-hole and in which a working fluid flows; and a wick formed in at least a part of the through-hole.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority from Korean PatentApplication No. 10-2010-0126771, filed on Dec. 13, 2010, with the KoreanIntellectual Property Office, the present disclosure of which isincorporated herein in its entirety by reference.

TECHNICAL FIELD

The present disclosure relates to a thin plate heat pipe usable incooling electronic components and equipment.

More particularly, the present disclosure relates to a thin plate heatpipe suitable for removing a hot spot in a flat panel display verticallyinstalled, such as an LCD TV, an LED TV, and a PDP TV.

BACKGROUND

Semiconductor components and systems packaged in electronic equipmenthave gradually been high-integrated and miniaturized with thedevelopment of a semiconductor manufacturing technology. Following thistrend, since heat emission density of components included in theelectronic equipment is significantly increased, a cooling mechanism foreffectively cooling and dissipating the emitted heat is required. Inparticular, since the electronic equipment is thinned together withminiaturization, an adopted cooling device also needs to be small-sized.

As an example of the cooling device in the related art which can beadopted in the small-sized electronic equipment, a heat sink, a fan, anda heat pipe having a circular cross section having a diameter of 3 mm ormore may be used.

Since the heat sink can be fabricated with various sizes and thicknessesand is low-priced, the heat sink has been widely used as a basic type ofcooling means in the meantime. However, when a significant micro size isrequired, a heat dissipation rate is relatively low with a decrease in aheat-transfer area.

The fan is limited in fabricating the fan with the micro size anddurability and reliability are relatively low.

The heat pipe in the related art may be crimped and used to be suitablefor a thin-film structure. However, since the small-sized heat pipehaving the circular structure cross section has a cross section which isinitially designed in a circular shape, when the small-sized heat pipeis crimped to be suitable for electronic equipment having thesmall-sized and thin-film structure, the heat-transfer performance issignificantly reduced due to a structural change of a wick.

Accordingly, a thin-film type minute heat pipe with a thickness ofapproximately 2 mm or less suitable for the electronic equipment havingthe small-sized and thin-film structure needs to be developed.

In recent years, particularly, the needs for emitted heat cooling andtemperature uniformity have been acute depending on performanceimprovement as well as diversification of products with the rapid growthof a display industry of a liquid crystal display (LCD) TV, a plasmadisplay panel (PDP) TV, and a light emitting diode (LED) TV. Inparticular, the display is significantly thinner and wider in responseto increased consumer's demands, such that emitted heat cooling andtemperature nonuniformity has become problematic.

Since a display device is vertically installed according to acharacteristic, the highest-temperature hot spot is generated at anupper part of the display by an effect of natural convection. A solutionfor uniformizing a temperature distribution vertically while removingthe hot spot is presently required.

SUMMARY

The present disclosure has been made in an effort to achieve highheat-transfer performance in an inclination mode in which a heat pipe isinstalled to form a predetermined angle with horizontality or in avertical mode in which the heat pipe is installed in a verticaldirection.

Further, the present disclosure relates to a heat pipe having a verysimple mechanical shape and the present disclosure has been made in aneffort to provide a thin plate heat pipe having an advantageousinclination angle to further improve productivity by fabricating theheat pipe through simple extrusion and insertion processes and variouslyapply to small-sized and thin-film structure electronic equipmentincluding a display.

An exemplary embodiment of the present disclosure provides a thin plateheat pipe including: a body part having a flat plate shape; athrough-hole formed in the body part in a longitudinal direction; aplurality of grooves formed on the inner wall of the through-hole and inwhich a working fluid flows; and a wick formed in at least a part of thethrough-hole.

The through-hole may be separated by one or more separation membranes.

The groove may have a shape including one or more edges.

The wick may be inserted into an evaporator section of the thin plateheat pipe.

The wick may be one of a sintered wick or a fabric wick.

The sintered wick may be inserted into the through-hole separated by oneor more separation membranes formed in the through-hole.

The sintered wick may be made of metal or ceramic.

The fabric wick may be integrally inserted into the through-hole.

The inside of the through-hole may be maintained in a vacuum state.

The thin plate heat pipe may be installed at an incline or vertically.

The heat pipe may be made of copper or aluminum.

The thickness of the heat pipe may be 2 mm or less.

According to the exemplary embodiments of the present disclosure, a thinplate heat pipe for a display that has a thin flat plate shape in whicha predetermined through-hole is formed therein and includes polygonallycross-sectional grooves having one or more edges formed on the innersurface of the through-hole to allow a liquid working fluid to flow bycapillary force generated from the edge, such that the excellentcapillary force can be acquired through structural transformation of theheat pipe itself and heat-transfer performance can be further improved.And the thinned flat plate heat pipe is fabricated in a simple processto further improve productivity and be variously applied to small-sizedand thin-film structure electronic equipment.

According to the exemplary embodiments of the present disclosure, aplurality of separation membranes are formed in one thin plate heatpipe, such that a plurality of passages can be formed using one thinplate heat pipe.

According to the exemplary embodiments of the present disclosure, notthroughout an overall length of the thin plate heat pipe, an additionalsintered wick is inserted into the center of the through-hole in apartial range of an evaporator section to generate large capillary forcerequired for the flowing of the working fluid. As such, the largecapillary force acquired by inserting the additional sintered wick intothe through-hole can show a large merit in heat-transfer performancewhen a display operates in an inclination mode.

According to the exemplary embodiments of the present disclosure, byinserting an additional fabric wick into the center of the through-holein the partial range of the evaporator section of the thin plate heatpipe, the large capillary force required for the flowing of the workingfluid can be acquired and weak solidity of the sintered wick can beovercome, thereby achieving a very wide industrial application range.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view for describing a thin plate heat pipeaccording to a first exemplary embodiment of the present disclosure.

FIG. 2 is a cross-sectional view for describing a thin plate heat pipeaccording to the first exemplary embodiment of the present disclosure.

FIG. 3 is a perspective view for describing a thin plate heat pipeaccording to a second exemplary embodiment of the present disclosure.

FIG. 4 is a cross-sectional view for describing a thin plate heat pipeaccording to the second exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawing, which form a part hereof. The illustrativeembodiments described in the detailed description, drawing, and claimsare not meant to be limiting. Other embodiments may be utilized, andother changes may be made, without departing from the spirit or scope ofthe subject matter presented here.

FIG. 1 is a perspective view for describing a thin plate heat pipe for adisplay according to a first exemplary embodiment of the presentdisclosure.

Referring to FIG. 1, the thin plate heat pipe for a display according tothe first exemplary embodiment of the present disclosure is constitutedby a relatively thin flat plate-shaped body part 100. The flatplate-shaped body part 100 may be configured as a pipe-type orpolyhedron-type metallic plate fabricated using the extrusion process.Body part 100 may be made of copper or aluminum and may be made of othermaterials except copper and aluminum depending on processability,corrosion resistance, durability, and the shape of a body part.

A predetermined through-hole 110 is formed in body part 110 to transporta working fluid injected from the outside. Through-hole 110 has an emptyspace with a predetermined shape.

A plurality of polygonal cross-section-shaped grooves 120 extended inthe same longitudinal direction as through-hole 110 are formed on theinner surface of through-hole 110. Capillary force is generated by edgesof the polygonal cross-section-shaped groove 120 to allow the liquidworking fluid to flow. For example, groove 120 may have a polygonalstructure having edges with various shapes such as a triangular shape, arectangular shape, a trapezoidal shape, a hemispherical shape, or aparabolic shape. For a design to generate optimal capillary force, thecross section may be optimally designed in terms of performance and costby adjusting the shape of groove 120 and the number and angles of theedges, and concave-convex portions of grooves 120.

A plurality of separation membranes 140 may be formed in through-hole110 in order to form a plurality of flow paths. When the width of theheat pipe is small, even one separation membrane may be enough, but whenthe width is large, the plurality of separation membranes may be formed.

As described above, in the thin plate heat pipe for a display accordingto the first exemplary embodiment of the present disclosure, the liquidworking fluid flows by the capillary force generated from the edges ofpolygonal and complicatedly-curved or concave-convex-shaped grooves 120,instead of a wick in the related art serving as a passage for allowingthe liquid working fluid to flow (return) from a condenser section to anevaporator section.

The liquid working fluid injected while the inside of the thin plateheat pipe for a display according to the first exemplary embodiment ofthe present disclosure configured as above is maintained in a vacuumstate serves to emit heat of the display to the outside and reduce thehot spot while the liquid working fluid performs the phase changesbetween liquid and gas. Therefore, the type of the liquid requires acharacteristic in which the liquid performs the phase changes betweenliquid and gas within an operational temperature range of the heat pipe.

The thin plate heat pipe for a display according to the first exemplaryembodiment of the present disclosure has a structure in which severalgrooves 120 extended in the longitudinal direction are formed on theinner surface of through-hole 110 and an additional sintered wick 130 isinserted into the middle of the inner surface of through-hole 110.

Since sintered wick 130 may generate relatively large capillary force,the working fluid may flow in a gravity direction (for example, avertical direction from the bottom to the top) when the display isinstalled in an inclination mode. In this case, a flowing direction ofthe working fluid in the inclination mode or a vertical mode may varydepending on detailed situations such as the position of the hot spotand the gravity direction.

As described above, the capillary force required for the flowing of theworking fluid is acquired by even an additionally inserted sintered wick130 as well as grooves 120 installed on the inner surface ofthrough-hole 110, such that the heat-transfer performance of the thinplate heat pipe can be significantly improved.

Meanwhile, sintered wick 130 is not installed throughout an overalllength of the heat pipe but at only at least one portion of theevaporator section unlike the sintered wick heat pipes in the relatedart. Further, as described above, a difference from the related art iseven in that sintered wick 130 is positioned at the center of thethrough-hole on the cross section of the heat pipe.

Sintered wick 130 may be fabricated using a metallic material and aceramic based material. Sintered wick 130 is separately inserted intothrough-hole 110 separated by separation membranes 140.

FIG. 2 is a cross-sectional view for describing a thin plate heat pipeaccording to the first exemplary embodiment of the present disclosure.

Referring to FIG. 2, the cross-sectional structure of through-hole 110,the shape of groove 120, and the structure of separation membrane 140 inthe thin plate heat pipe according to the first exemplary embodiment ofthe present disclosure can be verified in detail.

In particular, additionally inserted sintered wick 130 is positioned ina middle space between grooves 120 installed on the wall of through-hole110 and is separated into pieces and inserted into each through-hole 110separated by separation membranes 140.

FIG. 3 is a perspective view for describing a thin plate heat pipe for adisplay according to a second exemplary embodiment of the presentdisclosure.

Referring to FIG. 3, the thin plate heat pipe for a display according tothe second exemplary embodiment of the present disclosure is constitutedby a thinned flat plate-shaped body part 300 similarly as in the firstexemplary embodiment of the present disclosure.

As described above, the thin plate heat pipe for a display according tothe second exemplary embodiment of the present disclosure has astructure and a function similar to the first exemplary embodiment. Thatis, the heat pipe has a relatively thin flat plate-shaped outer profileand has a longitudinal through-hole 310 therein. A plurality oflongitudinal grooves are formed on the inner surface of through hole 310to seal the working fluid which performs the phase change within theoperational temperature range of the heat pipe, such that the workingfluid flows in a liquid phase through the groove and the wick isincluded in the through-hole. However, the wick additionally insertedinto the center of through-hole 310 is constituted by a wick 330 made ofa fiber material.

In the thin plate heat pipe for a display according to the firstexemplary embodiment, the wick inserted to generate large capillaryforce is sintered wick 103, but in the thin plate heat pipe for adisplay according to the second exemplary embodiment, a fabric wick 303is inserted, such that large capillary force can be generated and astructural demerit in which sintered wick 130 tends to be easily brokencan be overcome.

As shown in FIG. 3, when fabric wick 330 is inserted into the center ofthrough-hole 310, the wick is not separated by separation membranes 340but integrally inserted into through-hole 310 while being not separatedwith being hung on separation membranes 340. As shown in FIG. 3,separation membranes 340 are not extended throughout the longitudinaldirection of body part 300 but may be formed at only the center otherthan the end. Further, fabric wick 330 may have a structure in which onewick is inserted into one separated through-hole similarly as insintered wick 103.

Meanwhile, since the thin plate heat pipe for a display according to thesecond exemplary embodiment of the present disclosure has the sameoperations and effects as the first exemplary embodiment of the presentdisclosure, a detailed description thereof may refer to the firstexemplary embodiment of the present disclosure.

FIG. 4 is a cross-sectional view for describing a thin plate heat pipefor a display according to the second exemplary embodiment of thepresent disclosure.

Referring to FIG. 4, the cross-sectional structure of through-hole 310,the shape of a groove 320, and the structure of separation membrane 340in the thin plate heat pipe according to the second exemplary embodimentof the present disclosure can be verified in detail.

In particular, additionally inserted fabric wick 330 is positioned inthe middle space between grooves 320 installed on the wall ofthrough-hole 310 and separation membranes 340 do not separate theentirety of body part 300, such that fabric wick 330 may be connectedthroughout through-hole 310.

As described above, the thin plate heat pipe for a display according tothe first and second exemplary embodiments of the present disclosure hasa minute thickness of approximately 2 mm or less and excellent heatdissipation and heat-transfer performance and in particular, shows avery effective operational characteristic in the inclination mode, andas a result, the thin plate heat pipe can be effectively used as meansto achieve removal of the hot spot and temperature uniformity of thedisplay.

Although the thin plate heat pipe for a display according to theexemplary embodiments of the present disclosure has been described,various modifications can be made within the scopes of the appendedclaims, the detailed description of the present disclosure, and theaccompanying drawings are also included in the present disclosure.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various embodiments disclosed herein are not intendedto be limiting, with the true scope and spirit being indicated by thefollowing claims.

1. A thin plate heat pipe, comprising: a body part having a flat plate shape; a through-hole formed in the body part in a longitudinal direction; a plurality of grooves formed on the inner wall of the through-hole and in which a working fluid flows; and a wick formed in at least a part of the through-hole.
 2. The thin plate heat pipe of claim 1, wherein the through-hole is separated by one or more separation membranes.
 3. The thin plate heat pipe of claim 1, wherein the groove has a shape including one or more edges.
 4. The thin plate heat pipe of claim 1, wherein the wick is inserted into an evaporator section of the thin plate heat pipe.
 5. The thin plate heat pipe of claim 1, wherein the wick is one of a sintered wick or a fabric wick.
 6. The thin plate heat pipe of claim 5, wherein the sintered wick is inserted into the through-hole separated by one or more separation membranes formed in the through-hole.
 7. The thin plate heat pipe of claim 6, wherein the sintered wick is made of metal or ceramic.
 8. The thin plate heat pipe of claim 5, wherein the fabric wick is integrally inserted into the through-hole.
 9. The thin plate heat pipe of claim 1, wherein the inside of the through-hole is maintained in a vacuum state.
 10. The thin plate heat pipe of claim 1, wherein the thin plate heat pipe is installed at an incline or vertically.
 11. The thin plate heat pipe of claim 1, wherein the heat pipe is made of copper or aluminum.
 12. The thin plate heat pipe of claim 1, wherein the thickness of the heat pipe is 2 mm or less. 